Transformer terminal



Dec. 28 1926.

J. B. HANSELL ET AL TRANSFORMER TERMINAL Filed May 7. 1.923

g kg g 0R5 nsell & ley.

INVENT John Benfley Ha BenediBcy' Bees ATTORNEY iii Patented Dec. 28, 1926.

UNITED STATES 1,612,373 PATENT OFFICE.

JGHN BENTLEY HANSELL AND BENEDICT BEESLEY, OF IJANOHESTER, ENGLAND, AS-

SIGNORS TO WESTINGHOUSE ELECTRIC 5 MANUFACTURING COMPANY,

PORATION OF PENNSYLVANIA.

COR-- TRANSFORMER TERIVIENAL.

Application filed May 7,

Our invention elates to terminals for electrical transformers and in particular to terminals for transformers which are to be located out of doors or in exposed situations although the improved terminals also be employed with transformers located under cover, that is to under ordinary conditions of use. I

In electrical transformers as at present generally constructed for outdoor use all tappings for the windings are broughtto the oil level but only one from each wind is extended through the cover of the tank or casing. Consequently when it is desired to change a connection from one tapping to another the tank cover has to be removed.

Transformer terminals in which a plurality of leads or tappings pass through a single insulating bushing have already been employed but such terminals were not weatherwoof or suitable for use in exposed situations.

An object of the present invention is to provide an improved construction of ter minal oil" the kind above mentioned which will be weather-proof and not readily at- :lected by external conditions so that it may be used in exposed situations where transformers are located in the open and not under cover.

lVith this object in view according to the invention the improved terminal comprises a substantially cylindrical insulating bushing containing a plurality of sockets insulated from each other and equi-distantly spaced from a common center with a re movable cap carrying a plug adapted to make electrical connection with any one of said sockets. he removable cap is adapted to fit over the end oi? the bushing and to be rotated about an axis passing through the common centre of the sockets so that the plug can be caused to engage with any de sired socket. In some cases the cap may be provided with two or more plugs one of which is adapted to ei'igagc with a centrally located socket in the insulating bushing.

In order that the invention may be more clearly understood and readily carried into practice, reference will now be made to the accom iianying drawings wherein two constructional forms are illustrated by way of example:

1923, Serial No. 631679. and in lil'iillil'l May 3-9. 3.322,

Figs. 1 and 2 are respectively vertical medial section and plan views of one form and Figs. 3 and l: similar views of the other form, the last named with the cap removed, with the electrical connections between same and a transformer indicated diagrammatically.

In each form illustrated the terminal comprises a substantially cylindrical hollow body portion 5 of porcelain or other suitable insulating material having on the part intended to be located outside the transformer tank or casing a number of sheds G and a circumferential groove 7 adjacent the end thereof. A number of metal sockets 8 corresponding to the number of tappings or leads from each winding of the transformer are embedded in cen'ient 9 near the end of the body portion of the terminal and arranged on the circiunl'erence of a circle concentric with said body portion. The terminal cap 10 is conveniently formed of sheet metal and has oppositely disposed internal projections 11 thereon engaging the circumferential groove 7 in the body portion or he terminal and carries a plug 12 in such a position as to be adapted to engage with any one of the sockets 8 in accordanre with the position to which the cap is rotated before it is sprung into position on the body portion and which terminates, above the cap, in a screwed portion carrying a wingnut 13.

The construction illustrated by F i 's. l and 2 is adapted for use in connection with a single phase or star connected three phase transformer both of which are represented diagrammatically at 14 the forn'ier by the full and the latter by both full and dotted lines, the cap 10 being connected by means of the wing-nut 13 to an outgoing conductor which it is desired shall be connected to the winding of a leg of the transformer and the sockets 8 connected to the end l5 and to the several tappings 16, 17 of the said winding. It will be obvious that by removing the cap and rotating it to the necessary posit-ion and then replacing same, connection can be made from the outgoing conductor to any one oi the tappings desired.

The construction illustrated by l igs. 3 and l is specially adapted for use with a deltaconnected three-phase transformer which is illustrateddiagrammatically at 18, an additionalcentral socket 19 beingprovided in the body portion and an additional central plug 20 in the cap. The socket 19 is connected to the end 21 of one phase winding of the transformer and the sockets 8 to the end 22 and to tappings 23, 24 from another phase winding of the transformer. It will be apparent that by rotating the cap to various positions an outgoing conductor connected thereto by means of the wing-nut l3 1nay be connected with the end of one phase winding and any one of the tappings from the other phase winding.

With two or three-terminals such as hereinbefore described external phase conductors may be connected to the phase windings of a singleor three-phasetransformer in such manner as to include any desired portion of the phase windings as permitted by the tappings.

It will be seen that the cap'lllprotects the terminal ends of the trappings of the trans former windings and a weather-proof construction readily obtained. liemoval ani'l replacement of the cap '10 is easily effected owing to the inherent resilience of the material oi which it is made or alternatively, the projections 11 which engage in the circumferential groove 7 may be resiliently mounted or any other suitableconstruction may be adapted to permit removal and re placement of the cap.

The ii'i'iproved terminal construction is not limited to three-phase transformers, and I:-

may-obviously be employed with either indoor or outdoor apparatus.

Having now particularly described and ascertained the nature of our said invention ed from one another and spaced equidistantly'from common center and an'adjustablc cap carrying a terminal plug adapted to selectively make electrical connection to any of the said sockets, the said cap being constituted to overlap the end of the bushing and shed moisture clear of the upper end of the bushing 2. A terminal for an electrical transformercomprising an insulating bushing having a plurality of sockets therein insulated troi'n one another and spaced equidistantly from a common center and. an adjustable cap carrying a terminal plug adapted to selectively make electrical connection to any oi? the said sockets, the said cap being constituted to seal the end of the bushing against the entrance of moisture.

In testimony whereof, we have hereunto subscribed our names this 18th day of April, 1923.

JOHN BENTLEY HANSELL. BENEDICT BEESLEY. 

